`NFTXZap`

Contracts/src/contracts/zaps/NFTXZap.sol
Interface: Contracts/src/interfaces/INFTXZap.sol

Convenience wrapper that lets users buy/sell NFTs with raw ETH (no intermediate flETH / CollectionToken bookkeeping). Internally the Zap wraps/unwraps flETH and routes through the V4 PoolManager + Listings.

The frontend’s “Buy now” / “Sell” buttons almost always use these entry-points. Hand-rolled Listings.fillListings is reserved for the cases where the user already holds CollectionToken directly (e.g. arbitrage flows).

Public surface

NFT ↔ ETH

Function	Description
`buyNFTWithETH(_collection, _tokenIdsOut, _minTokensReceived, _maxETHSpent)`	ETH → flETH → CT → fill listings → NFT to user. Returns `ethSpent_`.
`sellNFTForETH(_collection, _tokenIds, _minETHReceived)`	NFT → Locker.deposit → swap CT→flETH → unwrap → ETH to user. Returns `ethReceived_`.
`redeemFloorWithETH(_collection, _tokenIds, _maxETHSpent)`	ETH → swap → CT → Locker.redeem → NFT to user. Returns `ethSpent_`.

Token ↔ ETH

Function	Description
`buyTokensWithETH(_collection, _minTokensReceived)`	ETH → flETH → swap → CT to user. Returns `tokensReceived_`.
`sellTokensForETH(_collection, _tokenAmount, _minETHReceived)`	CT → swap → flETH → ETH to user. Returns `ethReceived_`.
`sellTokensForETHWithPermit2(_collection, _tokenAmount, _minETHReceived, _deadline, _nonce, _signature)`	Same as `sellTokensForETH` but pulls the CT via Permit2 SignatureTransfer (no separate approval tx).

Sandwich + slippage protection

Every entry-point exposes either a min/max bound on the realised swap output, and the buy paths thread FillListingsParams.maxSpend through to Listings.fillListings:

_minTokensReceived / _minETHReceived — slippage on the V4 swap itself.
_maxETHSpent (on buyNFTWithETH / redeemFloorWithETH) — hard cap on total ETH spent. Reverts with ExcessiveInput if exceeded.
The combination defends against Listings.modifyListings front-runs that move listing prices upward between simulation and execution.

Errors

Error	Cause
`CollectionNotInitialized`	Pool not bootstrapped
`InsufficientOutput(received, minimum)`	Swap output below `_minTokensReceived` / `_minETHReceived`
`ExcessiveInput(spent, maximum)`	Realised spend above `_maxETHSpent`
`NoTokenIds`	Empty array
`ZeroTokenAmount`	`_tokenAmount == 0`
`UnauthorizedETHSender`	ETH received from a contract that isn’t the Zap’s expected counterparty (flETH / V4 router)

Events

Event	Trigger
`NFTBoughtWithETH(_collection, _nftCount, _ethSpent, _buyer)`	`buyNFTWithETH`
`NFTSoldForETH(_collection, _tokenIds, _ethReceived, _seller)`	`sellNFTForETH`
`TokensBoughtWithETH(_collection, _tokensReceived, _ethSpent, _buyer)`	`buyTokensWithETH`
`TokensSoldForETH(_collection, _tokensSold, _ethReceived, _seller)`	`sellTokensForETH`
`FloorRedeemedWithETH(_collection, _tokenIds, _ethSpent, _redeemer)`	`redeemFloorWithETH`

Inherited surface

ReentrancyGuard.
A guarded receive() so only flETH / the V4 router can send ETH.

TaxCalculator